1 /*
2 * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import sun.invoke.util.VerifyAccess;
29
30 import java.lang.reflect.Constructor;
31 import java.lang.reflect.Field;
32 import java.lang.reflect.Member;
33 import java.lang.reflect.Method;
34 import java.lang.reflect.Modifier;
35 import java.util.Objects;
36
37 import static java.lang.invoke.MethodHandleNatives.Constants.*;
38 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
39 import static java.lang.invoke.MethodHandleStatics.newInternalError;
40
41 /**
42 * A {@code MemberName} is a compact symbolic datum which fully characterizes
43 * a method or field reference.
44 * A member name refers to a field, method, constructor, or member type.
45 * Every member name has a simple name (a string) and a type (either a Class or MethodType).
46 * A member name may also have a non-null declaring class, or it may be simply
47 * a naked name/type pair.
48 * A member name may also have non-zero modifier flags.
49 * Finally, a member name may be either resolved or unresolved.
50 * If it is resolved, the existence of the named member has been determined by the JVM.
51 * <p>
52 * Whether resolved or not, a member name provides no access rights or
53 * invocation capability to its possessor. It is merely a compact
54 * representation of all symbolic information necessary to link to
55 * and properly use the named member.
56 * <p>
57 * When resolved, a member name's internal implementation may include references to JVM metadata.
58 * This representation is stateless and only descriptive.
59 * It provides no private information and no capability to use the member.
60 * <p>
61 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
62 * about the internals of a method (except its bytecodes) and also
63 * allows invocation. A MemberName is much lighter than a Method,
64 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
65 * and those seven fields omit much of the information in Method.
66 * @author jrose
67 */
68 /*non-public*/
69 final class ResolvedMethodName {
70 //@Injected JVM_Method* vmtarget;
71 //@Injected Class<?> vmholder;
72 }
73
74 /*non-public*/
75 final class MemberName implements Member, Cloneable {
76 private Class<?> clazz; // class in which the member is defined
77 private String name; // may be null if not yet materialized
78 private Object type; // may be null if not yet materialized
79 private int flags; // modifier bits; see reflect.Modifier
80 private ResolvedMethodName method; // cached resolved method information
81 //@Injected intptr_t vmindex; // vtable index or offset of resolved member
82 Object resolution; // if null, this guy is resolved
83
84 /** Return the declaring class of this member.
85 * In the case of a bare name and type, the declaring class will be null.
86 */
87 public Class<?> getDeclaringClass() {
88 return clazz;
89 }
90
91 /** Utility method producing the class loader of the declaring class. */
92 public ClassLoader getClassLoader() {
93 return clazz.getClassLoader();
94 }
95
96 /** Return the simple name of this member.
97 * For a type, it is the same as {@link Class#getSimpleName}.
98 * For a method or field, it is the simple name of the member.
99 * For a constructor, it is always {@code "<init>"}.
100 */
101 public String getName() {
102 if (name == null) {
103 expandFromVM();
104 if (name == null) {
105 return null;
106 }
107 }
108 return name;
109 }
110
111 public MethodType getMethodOrFieldType() {
112 if (isInvocable())
113 return getMethodType();
114 if (isGetter())
115 return MethodType.methodType(getFieldType());
116 if (isSetter())
117 return MethodType.methodType(void.class, getFieldType());
118 throw new InternalError("not a method or field: "+this);
119 }
120
121 /** Return the declared type of this member, which
122 * must be a method or constructor.
123 */
124 public MethodType getMethodType() {
125 if (type == null) {
126 expandFromVM();
127 if (type == null) {
128 return null;
129 }
130 }
131 if (!isInvocable()) {
132 throw newIllegalArgumentException("not invocable, no method type");
133 }
134
135 {
136 // Get a snapshot of type which doesn't get changed by racing threads.
137 final Object type = this.type;
138 if (type instanceof MethodType mt) {
139 return mt;
140 }
141 }
142
143 // type is not a MethodType yet. Convert it thread-safely.
144 synchronized (this) {
145 if (type instanceof String sig) {
146 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
147 type = res;
148 } else if (type instanceof Object[] typeInfo) {
149 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
150 Class<?> rtype = (Class<?>) typeInfo[0];
151 MethodType res = MethodType.methodType(rtype, ptypes, true);
152 type = res;
153 }
154 // Make sure type is a MethodType for racing threads.
155 assert type instanceof MethodType : "bad method type " + type;
156 }
157 return (MethodType) type;
158 }
159
160 /** Return the descriptor of this member, which
161 * must be a method or constructor.
162 */
163 String getMethodDescriptor() {
164 if (type == null) {
165 expandFromVM();
166 if (type == null) {
167 return null;
168 }
169 }
170 if (!isInvocable()) {
171 throw newIllegalArgumentException("not invocable, no method type");
172 }
173
174 // Get a snapshot of type which doesn't get changed by racing threads.
175 final Object type = this.type;
176 if (type instanceof String str) {
177 return str;
178 } else {
179 return getMethodType().toMethodDescriptorString();
180 }
181 }
182
183 /** Return the actual type under which this method or constructor must be invoked.
184 * For non-static methods or constructors, this is the type with a leading parameter,
185 * a reference to declaring class. For static methods, it is the same as the declared type.
186 */
187 public MethodType getInvocationType() {
188 MethodType itype = getMethodOrFieldType();
189 if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
190 return itype.changeReturnType(clazz);
191 if (!isStatic())
192 return itype.insertParameterTypes(0, clazz);
193 return itype;
194 }
195
196 /** Return the declared type of this member, which
197 * must be a field or type.
198 * If it is a type member, that type itself is returned.
199 */
200 public Class<?> getFieldType() {
201 if (type == null) {
202 expandFromVM();
203 if (type == null) {
204 return null;
205 }
206 }
207 if (isInvocable()) {
208 throw newIllegalArgumentException("not a field or nested class, no simple type");
209 }
210
211 {
212 // Get a snapshot of type which doesn't get changed by racing threads.
213 final Object type = this.type;
214 if (type instanceof Class<?> cl) {
215 return cl;
216 }
217 }
218
219 // type is not a Class yet. Convert it thread-safely.
220 synchronized (this) {
221 if (type instanceof String sig) {
222 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
223 Class<?> res = mtype.returnType();
224 type = res;
225 }
226 // Make sure type is a Class for racing threads.
227 assert type instanceof Class<?> : "bad field type " + type;
228 }
229 return (Class<?>) type;
230 }
231
232 /** Utility method to produce either the method type or field type of this member. */
233 public Object getType() {
234 return (isInvocable() ? getMethodType() : getFieldType());
235 }
236
237 /** Return the modifier flags of this member.
238 * @see java.lang.reflect.Modifier
239 */
240 public int getModifiers() {
241 return (flags & RECOGNIZED_MODIFIERS);
242 }
243
244 /** Return the reference kind of this member, or zero if none.
245 */
246 public byte getReferenceKind() {
247 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
248 }
249 private boolean referenceKindIsConsistent() {
250 byte refKind = getReferenceKind();
251 if (refKind == REF_NONE) return isType();
252 if (isField()) {
253 assert(staticIsConsistent());
254 assert(MethodHandleNatives.refKindIsField(refKind));
255 } else if (isConstructor()) {
256 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
257 } else if (isMethod()) {
258 assert(staticIsConsistent());
259 assert(MethodHandleNatives.refKindIsMethod(refKind));
260 if (clazz.isInterface())
261 assert(refKind == REF_invokeInterface ||
262 refKind == REF_invokeStatic ||
263 refKind == REF_invokeSpecial ||
264 refKind == REF_invokeVirtual && isObjectPublicMethod());
265 } else {
266 assert(false);
267 }
268 return true;
269 }
270 private boolean isObjectPublicMethod() {
271 if (clazz == Object.class) return true;
272 MethodType mtype = getMethodType();
273 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
274 return true;
275 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
276 return true;
277 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
278 return true;
279 return false;
280 }
281
282 /*non-public*/
283 boolean referenceKindIsConsistentWith(int originalRefKind) {
284 int refKind = getReferenceKind();
285 if (refKind == originalRefKind) return true;
286 if (getClass().desiredAssertionStatus()) {
287 switch (originalRefKind) {
288 case REF_invokeInterface -> {
289 // Looking up an interface method, can get (e.g.) Object.hashCode
290 assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this;
291 }
292 case REF_invokeVirtual, REF_newInvokeSpecial -> {
293 // Looked up a virtual, can get (e.g.) final String.hashCode.
294 assert (refKind == REF_invokeSpecial) : this;
295 }
296 default -> {
297 assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
298 }
299 }
300 }
301 return true;
302 }
303 private boolean staticIsConsistent() {
304 byte refKind = getReferenceKind();
305 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
306 }
307 private boolean vminfoIsConsistent() {
308 byte refKind = getReferenceKind();
309 assert(isResolved()); // else don't call
310 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
311 assert(vminfo instanceof Object[]);
312 long vmindex = (Long) ((Object[])vminfo)[0];
313 Object vmtarget = ((Object[])vminfo)[1];
314 if (MethodHandleNatives.refKindIsField(refKind)) {
315 assert(vmindex >= 0) : vmindex + ":" + this;
316 assert(vmtarget instanceof Class);
317 } else {
318 if (MethodHandleNatives.refKindDoesDispatch(refKind))
319 assert(vmindex >= 0) : vmindex + ":" + this;
320 else
321 assert(vmindex < 0) : vmindex;
322 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
323 }
324 return true;
325 }
326
327 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
328 assert(getReferenceKind() == oldKind && MethodHandleNatives.refKindIsValid(refKind));
329 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
330 return this;
331 }
332
333 private boolean matchingFlagsSet(int mask, int flags) {
334 return (this.flags & mask) == flags;
335 }
336 private boolean allFlagsSet(int flags) {
337 return (this.flags & flags) == flags;
338 }
339 private boolean anyFlagSet(int flags) {
340 return (this.flags & flags) != 0;
341 }
342
343 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
344 */
345 public boolean isMethodHandleInvoke() {
346 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
347 final int negs = Modifier.STATIC;
348 if (matchingFlagsSet(bits | negs, bits) && clazz == MethodHandle.class) {
349 return isMethodHandleInvokeName(name);
350 }
351 return false;
352 }
353 public static boolean isMethodHandleInvokeName(String name) {
354 return switch (name) {
355 case "invoke", "invokeExact" -> true;
356 default -> false;
357 };
358 }
359 public boolean isVarHandleMethodInvoke() {
360 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
361 final int negs = Modifier.STATIC;
362 if (matchingFlagsSet(bits | negs, bits) && clazz == VarHandle.class) {
363 return isVarHandleMethodInvokeName(name);
364 }
365 return false;
366 }
367 public static boolean isVarHandleMethodInvokeName(String name) {
368 try {
369 VarHandle.AccessMode.valueFromMethodName(name);
370 return true;
371 } catch (IllegalArgumentException e) {
372 return false;
373 }
374 }
375 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
376
377 /** Utility method to query the modifier flags of this member. */
378 public boolean isStatic() {
379 return Modifier.isStatic(flags);
380 }
381 /** Utility method to query the modifier flags of this member. */
382 public boolean isPublic() {
383 return Modifier.isPublic(flags);
384 }
385 /** Utility method to query the modifier flags of this member. */
386 public boolean isPrivate() {
387 return Modifier.isPrivate(flags);
388 }
389 /** Utility method to query the modifier flags of this member. */
390 public boolean isProtected() {
391 return Modifier.isProtected(flags);
392 }
393 /** Utility method to query the modifier flags of this member. */
394 public boolean isFinal() {
395 return Modifier.isFinal(flags);
396 }
397 /** Utility method to query whether this member or its defining class is final. */
398 public boolean canBeStaticallyBound() {
399 return Modifier.isFinal(flags | clazz.getModifiers());
400 }
401 /** Utility method to query the modifier flags of this member. */
402 public boolean isVolatile() {
403 return Modifier.isVolatile(flags);
404 }
405 /** Utility method to query the modifier flags of this member. */
406 public boolean isAbstract() {
407 return Modifier.isAbstract(flags);
408 }
409 /** Utility method to query the modifier flags of this member. */
410 public boolean isNative() {
411 return Modifier.isNative(flags);
412 }
413 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
414
415 // unofficial modifier flags, used by HotSpot:
416 static final int BRIDGE = 0x00000040;
417 static final int VARARGS = 0x00000080;
418 static final int SYNTHETIC = 0x00001000;
419 static final int ANNOTATION= 0x00002000;
420 static final int ENUM = 0x00004000;
421 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
422 public boolean isBridge() {
423 return allFlagsSet(IS_METHOD | BRIDGE);
424 }
425 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
426 public boolean isVarargs() {
427 return allFlagsSet(VARARGS) && isInvocable();
428 }
429 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
430 public boolean isSynthetic() {
431 return allFlagsSet(SYNTHETIC);
432 }
433
434 static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular
435
436 // modifiers exported by the JVM:
437 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
438
439 // private flags, not part of RECOGNIZED_MODIFIERS:
440 static final int
441 IS_METHOD = MN_IS_METHOD, // method (not constructor)
442 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
443 IS_FIELD = MN_IS_FIELD, // field
444 IS_TYPE = MN_IS_TYPE, // nested type
445 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
446 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field
447
448 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
449 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
450 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
451
452 /** Utility method to query whether this member is a method or constructor. */
453 public boolean isInvocable() {
454 return anyFlagSet(IS_INVOCABLE);
455 }
456 /** Query whether this member is a method. */
457 public boolean isMethod() {
458 return allFlagsSet(IS_METHOD);
459 }
460 /** Query whether this member is a constructor. */
461 public boolean isConstructor() {
462 return allFlagsSet(IS_CONSTRUCTOR);
463 }
464 /** Query whether this member is a field. */
465 public boolean isField() {
466 return allFlagsSet(IS_FIELD);
467 }
468 /** Query whether this member is a type. */
469 public boolean isType() {
470 return allFlagsSet(IS_TYPE);
471 }
472 /** Utility method to query whether this member is neither public, private, nor protected. */
473 public boolean isPackage() {
474 return !anyFlagSet(ALL_ACCESS);
475 }
476 /** Query whether this member has a CallerSensitive annotation. */
477 public boolean isCallerSensitive() {
478 return allFlagsSet(CALLER_SENSITIVE);
479 }
480 /** Query whether this member is a trusted final field. */
481 public boolean isTrustedFinalField() {
482 return allFlagsSet(TRUSTED_FINAL | IS_FIELD);
483 }
484
485 /**
486 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
487 */
488 public boolean refersTo(Class<?> declc, String n) {
489 return clazz == declc && getName().equals(n);
490 }
491
492 /** Initialize a query. It is not resolved. */
493 private void init(Class<?> defClass, String name, Object type, int flags) {
494 // defining class is allowed to be null (for a naked name/type pair)
495 //name.toString(); // null check
496 //type.equals(type); // null check
497 // fill in fields:
498 this.clazz = defClass;
499 this.name = name;
500 this.type = type;
501 this.flags = flags;
502 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet
503 //assert(referenceKindIsConsistent()); // do this after resolution
504 }
505
506 /**
507 * Calls down to the VM to fill in the fields. This method is
508 * synchronized to avoid racing calls.
509 */
510 private void expandFromVM() {
511 if (type != null) {
512 return;
513 }
514 if (!isResolved()) {
515 return;
516 }
517 MethodHandleNatives.expand(this);
518 }
519
520 // Capturing information from the Core Reflection API:
521 private static int flagsMods(int flags, int mods, byte refKind) {
522 assert((flags & RECOGNIZED_MODIFIERS) == 0
523 && (mods & ~RECOGNIZED_MODIFIERS) == 0
524 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0);
525 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
526 }
527 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
528 public MemberName(Method m) {
529 this(m, false);
530 }
531 @SuppressWarnings("LeakingThisInConstructor")
532 public MemberName(Method m, boolean wantSpecial) {
533 Objects.requireNonNull(m);
534 // fill in vmtarget, vmindex while we have m in hand:
535 MethodHandleNatives.init(this, m);
536 if (clazz == null) { // MHN.init failed
537 if (m.getDeclaringClass() == MethodHandle.class &&
538 isMethodHandleInvokeName(m.getName())) {
539 // The JVM did not reify this signature-polymorphic instance.
540 // Need a special case here.
541 // See comments on MethodHandleNatives.linkMethod.
542 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
543 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
544 init(MethodHandle.class, m.getName(), type, flags);
545 if (isMethodHandleInvoke())
546 return;
547 }
548 if (m.getDeclaringClass() == VarHandle.class &&
549 isVarHandleMethodInvokeName(m.getName())) {
550 // The JVM did not reify this signature-polymorphic instance.
551 // Need a special case here.
552 // See comments on MethodHandleNatives.linkMethod.
553 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
554 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
555 init(VarHandle.class, m.getName(), type, flags);
556 if (isVarHandleMethodInvoke())
557 return;
558 }
559 throw new LinkageError(m.toString());
560 }
561 assert(isResolved());
562 this.name = m.getName();
563 if (this.type == null)
564 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
565 if (wantSpecial) {
566 if (isAbstract())
567 throw new AbstractMethodError(this.toString());
568 if (getReferenceKind() == REF_invokeVirtual)
569 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
570 else if (getReferenceKind() == REF_invokeInterface)
571 // invokeSpecial on a default method
572 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
573 }
574 }
575 public MemberName asSpecial() {
576 switch (getReferenceKind()) {
577 case REF_invokeSpecial: return this;
578 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
579 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
580 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
581 }
582 throw new IllegalArgumentException(this.toString());
583 }
584 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
585 * In that case it must already be REF_invokeSpecial.
586 */
587 public MemberName asConstructor() {
588 switch (getReferenceKind()) {
589 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
590 case REF_newInvokeSpecial: return this;
591 }
592 throw new IllegalArgumentException(this.toString());
593 }
594 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
595 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
596 * The end result is to get a fully virtualized version of the MN.
597 * (Note that resolving in the JVM will sometimes devirtualize, changing
598 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
599 * in some corner cases to either of the previous two; this transform
600 * undoes that change under the assumption that it occurred.)
601 */
602 public MemberName asNormalOriginal() {
603 byte refKind = getReferenceKind();
604 byte newRefKind = switch (refKind) {
605 case REF_invokeInterface,
606 REF_invokeVirtual,
607 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
608 default -> refKind;
609 };
610 if (newRefKind == refKind)
611 return this;
612 MemberName result = clone().changeReferenceKind(newRefKind, refKind);
613 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
614 return result;
615 }
616 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
617 @SuppressWarnings("LeakingThisInConstructor")
618 public MemberName(Constructor<?> ctor) {
619 Objects.requireNonNull(ctor);
620 // fill in vmtarget, vmindex while we have ctor in hand:
621 MethodHandleNatives.init(this, ctor);
622 assert(isResolved() && this.clazz != null);
623 this.name = CONSTRUCTOR_NAME;
624 if (this.type == null)
625 this.type = new Object[] { void.class, ctor.getParameterTypes() };
626 }
627 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
628 */
629 public MemberName(Field fld) {
630 this(fld, false);
631 }
632 static {
633 // the following MemberName constructor relies on these ranges matching up
634 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
635 }
636 @SuppressWarnings("LeakingThisInConstructor")
637 public MemberName(Field fld, boolean makeSetter) {
638 Objects.requireNonNull(fld);
639 // fill in vmtarget, vmindex while we have fld in hand:
640 MethodHandleNatives.init(this, fld);
641 assert(isResolved() && this.clazz != null);
642 this.name = fld.getName();
643 this.type = fld.getType();
644 byte refKind = this.getReferenceKind();
645 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
646 if (makeSetter) {
647 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
648 }
649 }
650 public boolean isGetter() {
651 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
652 }
653 public boolean isSetter() {
654 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
655 }
656
657 /** Create a name for the given class. The resulting name will be in a resolved state. */
658 public MemberName(Class<?> type) {
659 init(type.getDeclaringClass(), type.getSimpleName(), type,
660 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
661 initResolved(true);
662 }
663
664 /**
665 * Create a name for a signature-polymorphic invoker.
666 * This is a placeholder for a signature-polymorphic instance
667 * (of MH.invokeExact, etc.) that the JVM does not reify.
668 * See comments on {@link MethodHandleNatives#linkMethod}.
669 */
670 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
671 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
672 }
673 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
674 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
675 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
676 assert(mem.isMethodHandleInvoke()) : mem;
677 return mem;
678 }
679
680 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
681 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
682 }
683 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
684 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
685 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
686 assert(mem.isVarHandleMethodInvoke()) : mem;
687 return mem;
688 }
689
690 // bare-bones constructor; the JVM will fill it in
691 MemberName() { }
692
693 // locally useful cloner
694 @Override protected MemberName clone() {
695 try {
696 return (MemberName) super.clone();
697 } catch (CloneNotSupportedException ex) {
698 throw newInternalError(ex);
699 }
700 }
701
702 /** Get the definition of this member name.
703 * This may be in a super-class of the declaring class of this member.
704 */
705 public MemberName getDefinition() {
706 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
707 if (isType()) return this;
708 MemberName res = this.clone();
709 res.clazz = null;
710 res.type = null;
711 res.name = null;
712 res.resolution = res;
713 res.expandFromVM();
714 assert(res.getName().equals(this.getName()));
715 return res;
716 }
717
718 @Override
719 @SuppressWarnings({"deprecation", "removal"})
720 public int hashCode() {
721 // Avoid autoboxing getReferenceKind(), since this is used early and will force
722 // early initialization of Byte$ByteCache
723 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
724 }
725
726 @Override
727 public boolean equals(Object that) {
728 return that instanceof MemberName mn && this.equals(mn);
729 }
730
731 /** Decide if two member names have exactly the same symbolic content.
732 * Does not take into account any actual class members, so even if
733 * two member names resolve to the same actual member, they may
734 * be distinct references.
735 */
736 public boolean equals(MemberName that) {
737 if (this == that) return true;
738 if (that == null) return false;
739 return this.clazz == that.clazz
740 && this.getReferenceKind() == that.getReferenceKind()
741 && Objects.equals(this.name, that.name)
742 && Objects.equals(this.getType(), that.getType());
743 }
744
745 // Construction from symbolic parts, for queries:
746 /** Create a field or type name from the given components:
747 * Declaring class, name, type, reference kind.
748 * The declaring class may be supplied as null if this is to be a bare name and type.
749 * The resulting name will in an unresolved state.
750 */
751 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
752 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
753 initResolved(false);
754 }
755 /** Create a method or constructor name from the given components:
756 * Declaring class, name, type, reference kind.
757 * It will be a constructor if and only if the name is {@code "<init>"}.
758 * The declaring class may be supplied as null if this is to be a bare name and type.
759 * The last argument is optional, a boolean which requests REF_invokeSpecial.
760 * The resulting name will in an unresolved state.
761 */
762 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
763 int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
764 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
765 initResolved(false);
766 }
767 /** Create a method, constructor, or field name from the given components:
768 * Reference kind, declaring class, name, type.
769 */
770 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
771 int kindFlags;
772 if (MethodHandleNatives.refKindIsField(refKind)) {
773 kindFlags = IS_FIELD;
774 if (!(type instanceof Class))
775 throw newIllegalArgumentException("not a field type");
776 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
777 kindFlags = IS_METHOD;
778 if (!(type instanceof MethodType))
779 throw newIllegalArgumentException("not a method type");
780 } else if (refKind == REF_newInvokeSpecial) {
781 kindFlags = IS_CONSTRUCTOR;
782 if (!(type instanceof MethodType) ||
783 !CONSTRUCTOR_NAME.equals(name))
784 throw newIllegalArgumentException("not a constructor type or name");
785 } else {
786 throw newIllegalArgumentException("bad reference kind "+refKind);
787 }
788 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
789 initResolved(false);
790 }
791
792 /** Query whether this member name is resolved.
793 * A resolved member name is one for which the JVM has found
794 * a method, constructor, field, or type binding corresponding exactly to the name.
795 * (Document?)
796 */
797 public boolean isResolved() {
798 return resolution == null;
799 }
800
801 void initResolved(boolean isResolved) {
802 assert(this.resolution == null); // not initialized yet!
803 if (!isResolved)
804 this.resolution = this;
805 assert(isResolved() == isResolved);
806 }
807
808 void checkForTypeAlias(Class<?> refc) {
809 if (isInvocable()) {
810 MethodType type;
811 if (this.type instanceof MethodType mt)
812 type = mt;
813 else
814 this.type = type = getMethodType();
815 if (type.erase() == type) return;
816 if (VerifyAccess.isTypeVisible(type, refc)) return;
817 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
818 } else {
819 Class<?> type;
820 if (this.type instanceof Class<?> cl)
821 type = cl;
822 else
823 this.type = type = getFieldType();
824 if (VerifyAccess.isTypeVisible(type, refc)) return;
825 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
826 }
827 }
828
829
830 /** Produce a string form of this member name.
831 * For types, it is simply the type's own string (as reported by {@code toString}).
832 * For fields, it is {@code "DeclaringClass.name/type"}.
833 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
834 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
835 * If the member is unresolved, a prefix {@code "*."} is prepended.
836 */
837 @SuppressWarnings("LocalVariableHidesMemberVariable")
838 @Override
839 public String toString() {
840 if (isType())
841 return type.toString(); // class java.lang.String
842 // else it is a field, method, or constructor
843 StringBuilder buf = new StringBuilder();
844 if (getDeclaringClass() != null) {
845 buf.append(getName(clazz));
846 buf.append('.');
847 }
848 String name = this.name; // avoid expanding from VM
849 buf.append(name == null ? "*" : name);
850 Object type = this.type; // avoid expanding from VM
851 if (!isInvocable()) {
852 buf.append('/');
853 buf.append(type == null ? "*" : getName(type));
854 } else {
855 buf.append(type == null ? "(*)*" : getName(type));
856 }
857 byte refKind = getReferenceKind();
858 if (refKind != REF_NONE) {
859 buf.append('/');
860 buf.append(MethodHandleNatives.refKindName(refKind));
861 }
862 //buf.append("#").append(System.identityHashCode(this));
863 return buf.toString();
864 }
865 private static String getName(Object obj) {
866 if (obj instanceof Class<?> cl)
867 return cl.getName();
868 return String.valueOf(obj);
869 }
870
871 public IllegalAccessException makeAccessException(String message, Object from) {
872 message = message + ": " + this;
873 if (from != null) {
874 if (from == MethodHandles.publicLookup()) {
875 message += ", from public Lookup";
876 } else {
877 Module m;
878 Class<?> plc;
879 if (from instanceof MethodHandles.Lookup lookup) {
880 from = lookup.lookupClass();
881 m = lookup.lookupClass().getModule();
882 plc = lookup.previousLookupClass();
883 } else {
884 m = ((Class<?>)from).getModule();
885 plc = null;
886 }
887 message += ", from " + from + " (" + m + ")";
888 if (plc != null) {
889 message += ", previous lookup " +
890 plc.getName() + " (" + plc.getModule() + ")";
891 }
892 }
893 }
894 return new IllegalAccessException(message);
895 }
896 private String message() {
897 if (isResolved())
898 return "no access";
899 else if (isConstructor())
900 return "no such constructor";
901 else if (isMethod())
902 return "no such method";
903 else
904 return "no such field";
905 }
906 public ReflectiveOperationException makeAccessException() {
907 String message = message() + ": " + this;
908 ReflectiveOperationException ex;
909 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
910 resolution instanceof NoSuchFieldError))
911 ex = new IllegalAccessException(message);
912 else if (isConstructor())
913 ex = new NoSuchMethodException(message);
914 else if (isMethod())
915 ex = new NoSuchMethodException(message);
916 else
917 ex = new NoSuchFieldException(message);
918 if (resolution instanceof Throwable res)
919 ex.initCause(res);
920 return ex;
921 }
922
923 /** Actually making a query requires an access check. */
924 /*non-public*/
925 static Factory getFactory() {
926 return Factory.INSTANCE;
927 }
928 /** A factory type for resolving member names with the help of the VM.
929 * TBD: Define access-safe public constructors for this factory.
930 */
931 /*non-public*/
932 static class Factory {
933 private Factory() { } // singleton pattern
934 static final Factory INSTANCE = new Factory();
935
936 /** Produce a resolved version of the given member.
937 * Super types are searched (for inherited members) if {@code searchSupers} is true.
938 * Access checking is performed on behalf of the given {@code lookupClass}.
939 * If lookup fails or access is not permitted, null is returned.
940 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
941 */
942 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
943 boolean speculativeResolve) {
944 MemberName m = ref.clone(); // JVM will side-effect the ref
945 assert(refKind == m.getReferenceKind());
946 try {
947 // There are 4 entities in play here:
948 // * LC: lookupClass
949 // * REFC: symbolic reference class (MN.clazz before resolution);
950 // * DEFC: resolved method holder (MN.clazz after resolution);
951 // * PTYPES: parameter types (MN.type)
952 //
953 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
954 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
955 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
956 //
957 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
958 // so it is safe to call a MH from any context.
959 //
960 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
961 // participate in method selection.
962 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
963 if (m == null && speculativeResolve) {
964 return null;
965 }
966 m.checkForTypeAlias(m.getDeclaringClass());
967 m.resolution = null;
968 } catch (ClassNotFoundException | LinkageError ex) {
969 // JVM reports that the "bytecode behavior" would get an error
970 assert(!m.isResolved());
971 m.resolution = ex;
972 return m;
973 }
974 assert(m.referenceKindIsConsistent());
975 m.initResolved(true);
976 assert(m.vminfoIsConsistent());
977 return m;
978 }
979 /** Produce a resolved version of the given member.
980 * Super types are searched (for inherited members) if {@code searchSupers} is true.
981 * Access checking is performed on behalf of the given {@code lookupClass}.
982 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
983 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
984 */
985 public <NoSuchMemberException extends ReflectiveOperationException>
986 MemberName resolveOrFail(byte refKind, MemberName m,
987 Class<?> lookupClass, int allowedModes,
988 Class<NoSuchMemberException> nsmClass)
989 throws IllegalAccessException, NoSuchMemberException {
990 assert lookupClass != null || allowedModes == LM_TRUSTED;
991 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
992 if (result.isResolved())
993 return result;
994 ReflectiveOperationException ex = result.makeAccessException();
995 if (ex instanceof IllegalAccessException iae) throw iae;
996 throw nsmClass.cast(ex);
997 }
998 /** Produce a resolved version of the given member.
999 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1000 * Access checking is performed on behalf of the given {@code lookupClass}.
1001 * If lookup fails or access is not permitted, return null.
1002 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1003 */
1004 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1005 assert lookupClass != null || allowedModes == LM_TRUSTED;
1006 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1007 if (result != null && result.isResolved())
1008 return result;
1009 return null;
1010 }
1011 }
1012 }